Hybrid construction by fusion of protoplasts of Endomycopsis fibuligera and Saccharomyces cerevisiae.

Protoplasts of an ethanol-producing strain of Saccharomyces cerevisiae (rho-, Cyc R, Ket R) and amylase-producing yeast Endomycopsis fibuligera (rho+, Cyc S, Ket S) were fused, which resulted in starch fermenting hybrids. The fusion frequency was 2 x 10(-7). The morphological appearance of the hybrids was similar to the petite parent S. cerevisiae strain. The amount of DNA in the hybrid was found to be slightly higher when compared with the individual parental strain.